Within two days, the fever disappeared. But a day later, when he came home from preschool, the Catonsville mom and her husband, Jon, noticed small red spots on the bottom of Jonah’s feet.

“I thought he got bit or was irritated from running around,” Posner says.

As a precaution, Jon Posner called the family pediatrician. The diagnosis: Hand, Foot and Mouth Disease, also known as HFMD.

HFMD is a common viral illness that often affects infants and children younger than 10 years old. Pediatricians say the illness makes the rounds regularly in summer and fall. But this winter, some pediatricians say they are seeing more cases than usual, as well as evidence of newer strains of the illness that affect adults.

At St. Joseph Medical Center, pediatrician Dr. Nardine Assaad says she has seen three times as many cases of HFMD over the past year in the emergency department and inpatient unit, compared to recent years.

“It sounds like it is a more virulent strain,” she says. “Usually, the adults don’t have it. This year, a lot of adults do. It’s very uncomfortable.”

Signs, Symptoms and Treatment

When Tracy Posner heard her son’s diagnosis she says she was petrified.

“I had heard horror stories,” she says. “I was really worried about it initially.”

But the illness’s moniker, as well as the myths surrounding it, can often be misleading, doctors say. For example, HFMD is not Foot and Mouth Disease (FMD) — a disease that affects animals like cattle, pigs and sheep.

HFMD is caused by viruses belonging to the Enterovirus group. Coxsackievirus A16 is the most common cause, says Dr. Tim Doran, chairman of pediatrics at Greater Baltimore Medical Center. Enterovirus 71 can also lead to the disease. There are at least 40 or 50 different strains, Doran says.

Most strains are relatively benign, but all are contagious, spreading through saliva and fecal matter.

The first noticeable symptom is usually a fever, Doran says. For some children, that is the only symptom. But for others, sores appear one or two days after the fever starts. Mouth sores tend to show up first. They begin as small, red spots and then begin to blister, causing sore throat and pain with swallowing, Doran says.

A skin rash with red spots can also show up on the palms and soles of the feet. The rash can also appear on the buttocks or in the genital area.

For Jonah, the spots only appeared on his feet. And when his sister Avery, then nine months old, came down with HFMD a few days after Jonah, she didn’t have any spots. But she did have a fever — and lost a toenail as a result of the illness, Posner says.

It’s not uncommon for children to lose a toenail or fingernail after experiencing HFMD, Doran says. The skin under and around the spots may also shed as children recover from the illness — a move that surprised Posner.

“I would not have thought the spots on (Jonah’s) feet were blisters,” Posner says. “They weren’t raised. But then his skin started shedding, and it was like a blister popped.”

Children with HFMD can get all or only some of the symptoms, doctors say. While they are most contagious during the first week of illness, the virus can remain in the body for several weeks after the fever has disappeared, Doran says.

In most cases, the best treatment is a pain reliever like acetaminophen to alleviate pain associated with swallowing, says Dr. David Monroe, medical director of the pediatric unit at Howard County General Hospital. Some children refuse to drink because their throats hurt so much, he says. They risk becoming dehydrated and then hospitalization. Once the pain reliever kicks in, push as many liquids as possible, he says.

“They have to keep taking in fluids, even if they don’t want solids,” Monroe says.

Popsicles and ice cream also work well, Doran says.

Most children recover within a few weeks without complications. But in more serious, rare cases, viral meningitis or brain inflammation can occur.

More cases, new strain

This year, both Assaad and Monroe say they are seeing more adults and teens with the illness. Once a person has a certain strain of HFMD, they are usually immune from contracting it again, doctors say.

But new strains could be the cause of the jump in teen and adult numbers, Monroe says. Immunity also can wane, he says.

“The hard part is, the adults and (older) children that present with symptoms seem to be more sick than the (younger) children,” he says.

For example, the fever can last longer or the sores can be more prevalent in adults and teens, doctors say.

A newer HFMD strain, known as Coxsackievirus A6, has been striking children around the world throughout the past few years. The Centers for Disease Control and Prevention documented some of the first cases in the United States in late 2011 and early 2012.

Doran saw two patients in his office with the strain in recent months.

A6 can affect younger and older children, he says. It can also cause a more severe, widespread rash resembling lesions from the herpes simplex virus.

Still, it can rarely cause significant harm, Doran says.

“Overall, it’s just a nuisance for a few days,” he says.

Within a week, both Posner children bounced back from their initial bouts with HFMD. But six weeks later, they came down with the illness again, most likely the result of a different strain.

This time, Tracy Posner knew what to look for, how to keep her children comfortable and how to push past those horror stories she heard early on.

“Of course you don’t want your kid to get sick,” she says. “It’s just a common childhood virus.”

TIPS:

There is no vaccine to protect children against HFMD. But, the Centers for Disease Control and Prevention recommend the following steps to reduce the risk of getting the illness:

• Wash your hands often, especially after changing diapers

• Thoroughly clean objects and surfaces (toys, doorknobs, etc.) that may be contaminated with a virus that causes HFMD

• Avoid close contact (like kissing and hugging) with people who are infected